The present invention relates to a tape cassette such as a magnetic tape cassette, a cleaning tape cassette or a video tape cassette.
In a conventional tape cassette, a magnetic tape is guided in a tape traveling path between the head house and the hubs in the cassette casing so that the magnetic tape is wound around or rewound from the hubs. The hubs are supported for rotation by circular peripheral wall portions for fitting the hubs, which are formed around axial holes formed in the casing in order to receive the shaft portions of the hub. Various auxiliary elements are installed in the head house, and therefore, reinforcing ribs or partition walls are formed in the head house, or the wall thickness of the casing is increased, or material having service durability is used for the casing so that it has a sufficient strength and durability.
In the conventional tape cassette, the thickness of the outer peripheral wall of the casing is made thicker than the thickness of the flat surface wall portion of the casing in order to increase the impact resistance. However, the conventional tape cassette has disadvantages as follows. There is a large scatter (variation) in the wall thickness at many portions; molding properties are not good and there are strains and deformation in the molded casing. Further, since the head house area at the front portion of the casing has many ribs and partition walls, there is concentration of resin when the resin is injected to form the casing, and they are often caused recesses in the molded product. When there is a change in the wall thickness of the casing, a stream of molten resin is changed whereby strains remain at the portion of the resin stream change and a thermal deformation is apt to occur. In particular, when a casing having a thin wall thickness is required, such undesirable tendency is increased, and there are conspicuous recesses on the surface of the casing whereby the appearance of the casing is poor.